What the Anesthesiologist Should Know before the Operative Procedure

Cystic hygroma (CH) (i.e., cystic lymphangioma) is a congenital cystic tumor-like mass representing a malformation of lymphatic tissue. Incidence is 1 in 12,000 births in the United States and affects both sexes equally. Etiology is failure of peripheral lymphatic vessels to flow into the jugular sacs or the jugular sacs fail to reunite with the venous system. Forty percent of cases present at birth, 50% present before the first year of life, and 80% to 90% by the end of the second year of life, usually as a painless, soft, compressible mass.

The most common site for CH is the neck with a 2:1 predilection for the left side of the neck. Seventy-five percent of cases present in the posterior triangle of the head and neck with possible extension over the larynx, orbit, lip, tongue, parotid, face, cheek, floor of the mouth, and base of the tongue. The anterior triangle (usually high up under the mandible) is a less common presentation. Giant cystic hygromas can involve both sides of the neck and face, other structures in the area and extend into the mediastinum. Cystic hygromas may occur in other primitive lymph sac locations (axilla, inguinal, mediastinum, and retroperitoneum.) CH may have single or multiple cysts with tendency to infiltrate surrounding tissue hindering complete surgical resection and raising recurrence rates.

Treatment is complete surgical removal with or without intralesional injection of sclerosing agents such as OK 432. Alternative methods of treatment (aspiration, radiation, observation) are deemed less efficacious.

1. What is the urgency of the surgery?

What is the risk of delay in order to obtain additional preoperative information?

CHs may cause acute upper airway obstruction with sudden neck swelling as a result of infection or hemorrhage into the lesion. Additionally, continued growth of the mass might make future surgery difficult.

Emergent

When a CH is associated with extensive involvement of hypopharynx, tongue, mouth floor and larynx, acute airway compromise can occur at birth. Large fetal neck obstructing CH untreated prenatally may result in life threatening neonatal airway obstruction leading to asphyxia requiring tracheal intubation and tracheostomy, neonatal death due to inability to ventilate, and secondary brain damage and handicaps of speech, swallowing and cosmesis

Urgent

Urgent tracheostomy may be required in patients with moderate airway compromise.

Elective

Minimal airway compromise due to CH allows elective surgical resection of CH to minimize risk of bleeding or infection with subsequent airway obstruction.

Prenatal diagnosis of cervical CH in the first trimester by fetal ultrasound allows visualization of these structures and assessment for potential acute airway compromise at birth. Antenatal MRI may provide further information on the anatomy of the lesion, relationship to the airway, and to discriminate cystic and solid components. Such lesions where the fetal airway is compromised by cervical or congenital obstructions may be amenable to the EXIT procedure. Planning for EXIT procedures with strategic multidisciplinary planning team measures may define the timing, site and mode of delivery, as well as that of attendant staff, roles, and equipment to secure the airway of the infant and allow complete surgical removal.

2. Preoperative evaluation

Presence of a mass at birth or shortly thereafter is most prominent sign of CH.

Interference with normal breathing and swallowing. Respiratory difficulty can vary from mild stridor to cyanosis and complete obstruction. Acute airway obstruction can occur during induction if cystic lesions are present in the upper airway. Airway should be examined for involvement of supraglottic and infraglottic structures. Repeated coughing signal potential airway encroachment and that there may be existing airway obstruction. Forty-one percent of children with CH involving the neck have been reported as sustaining significant upper airway and feeding problems with risk factors cyst size, site and extension.

Severe dysphagia, feeding difficulties, and articulation difficulties due to extension of CH in the oral cavity into the tongue, mouth, and pharynx causing pediatric macroglossia, mandibular enlargement and pharyngeal obstruction. Child may present as malnourished or dehydrated, intravenous therapy is then required before surgery.

Dental caries may be secondary to poor oral and dental hygiene.

Tracheal compression is possible with larger cysts if extension occurs into the mediastinum. The child should be assessed carefully for evidence of intrathoracic extension.

Inflammation and infection of cysts can occur at any time.

Prenatally diagnosed first or early second-trimester CH have strong genetic association with Turner’s syndrome, Down syndrome, Edwards syndrome (trisomy 18), trisomy 13, Klippel-Trenaunay syndrome, Noonan syndrome, Fryn syndrome, and fetal hydrops. In these cases, anesthetic management is guided by the underlying syndrome. Associated anomalies are uncommon and include congenital glaucoma, ventricular septal defect, hydrocele, neurofibroma of the scalp and pyloric stenosis. Isolated CH diagnosed after 30 weeks of gestation has a better prognosis and is not associated with karyotypic, associated anomalies, or fetal hydrops.

Medically unstable conditions warranting further evaluation include signs and symptoms of airway obstruction if cystic lesions are present in the upper airway.

Delaying surgery may be indicated if the tumor has interfered with swallowing and the child is malnourished and dehydrated, and intravenous fluid therapy (lactated Ringer's or normal saline) is required before surgery.

3. What are the implications of co-existing disease on perioperative care?

Perioperative evaluation

Existing airway obstruction due to intraoral extension and possible intrathoracic extension may impact anesthetic induction and create a difficult airway

Perioperative risk reduction strategies

Avoidance of heavy sedation, availability of blood products for transfusion, preparation for difficult ventilation, and intubation with various endotracheal tubes and laryngoscope blades. Fiberoptic scope or glidescope may be helpful.

c. Pulmonary:

N/A

d. Renal-GI:

N/A

e. Neurologic:

N/A

f. Endocrine:

N/A

g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (e.g., musculoskeletal in orthopedic procedures, hematologic in a cancer patient)

N/A

4. What are the patient's medications and how should they be managed in the perioperative period?

N/A

h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?

N/A

i. What should be recommended with regard to continuation of medications taken chronically?

j. How to modify care for patients with known allergies

l. Does the patient have any antibiotic allergies - Common antibiotic allergies and alternative antibiotics

If a patient is allergic to beta-lactams, use fluoroquinolones and clindamycin in selected situations.

m. Does the patient have a history of allergy to anesthesia?

Malignant hyperthermia (MH)

Documented: Avoid all trigger agents such as succinylcholine and inhalational agents. Follow a proposed general anesthetic plan: total intravenous anesthesia with propofol ± opioid infusion ± nitrous oxide. Ensure that an MH cart is available [MH protocol].

5. What laboratory tests should be obtained and has everything been reviewed?

Laboratory tests include hemoglobin/hematocrit, type and screen, and chest radiography.

Hemoglobin level and type and screen should be obtained preoperatively, if extensive dissection and excision are planned or if the mass is located near the vascular structures of the neck.

Also obtain type and cross.

Chest radiographs are obtained to evaluate displacement of the trachea (possible difficult ventilation or intubation) and exclude intrathoracic extension extending from neck to mediastinum. Lateral X-ray of neck may reveal almost complete airway compression at level of epiglottis.

CT or MRI may assist delineation of lesions in parapharyngeal space and true limits of hygroma. CT scan may define compression of upper airway. MRI may delineate spread and evaluate airway patency for tumor in the mediastinum. CT scan may identify cardiopulmonary involvement and changes with respiration.

Fluoroscopy and angiography may aid in defining cardiopulmonary involvement in mediastinal involvement.

Administer first trimester ultrasound for routine prenatal diagnosis of fetal CH in the neck.

Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?

Consultation with the surgeon on the extent of the surgery including possibility of nerve monitoring is necessary to formulate an anesthetic plan. Anesthetic management of these patients should be cautious in case of respiratory embarrassment. Considerations on premedication should be mindful of avoidance of heavy sedation in the setting of potential airway compromise. Inhalation induction is the preferred technique for management of a difficult pediatric airway. Preservation of spontaneous breathing under sevoflurane with fentanyl/midazolam, midazolam/ketamine, or low-dose remifentanil. Dexmedetomidine may also be helpful. Neuromuscular blocking drugs should be avoided during induction of anesthesia.

In the case of marked pharyngeal involvement, identification of the site of the larynx may only be through visualization of bubbles of expired gas. Swollen pharyngeal tissue, macroglossia, or epiglottic involvement can easily cause respiratory obstruction, and ventilation may be impossible if neuromuscular blocking drugs are given.

Techniques to secure the airway include direct laryngoscopy, rigid bronchoscopy (bougie to exchange for endotracheal tube), fiberoptic intubation, video laryngoscope (glidescope), and tracheostomy. Attempts at direct laryngoscopy should be limited in cases of airway obstruction. Fiberoptic intubation may be required if the larynx is distorted by the lesions in which case spontaneous ventilation should be maintained until the airway is secured. Under EXIT procedure, airway may be secured by direct laryngoscopy and/or rigid bronchoscopy, Cook catheter via rigid bronchoscope.

Blood loss, fluid management, and hypothermia may occur with extensive dissection, necessitating availability of blood products, hydration, and warming modalities. Temporary urinary catheter may be placed if the procedure is expected to last more than 3 to 4 hours.

Ensure availability of blood and blood products for transfusion. Complete removal of tumor may involve extensive dissection and be accompanied by major blood loss.

General Anesthesia

Benefits:The technique of choice due to inability of young children to cooperate. Gradual onset of anesthesia by inhalation induction with facemask is easily titratable and safe, achieves a calm patient who is neither restless nor straining, and mitigates risk of worsening of airway obstruction (forced expiration worsens narrowing of airway).

General anesthesia is also the best technique for the EXIT procedure because it allows the use of high concentrations of inhalational agents that promote uterine relaxation and fetal anesthesia.

Drawbacks: Possible difficult mask ventilation and difficult intubation can occur. Airway of a neonate with a large CH may become obstructed after the induction of general anesthesia. Possible worsening of airway obstruction due to changes in intrapleural and intrathoracic pressures. Should airway obstruction arise, sevoflurane can be turned off and child awakened.

Other issues: Induction and maintenance of general anesthesia is practitioner dependent and will vary with the severity of the mass and degree of airway obstruction. During induction of anesthesia it is necessary to maintain spontaneous breathing since in the worst cases the only way to identify the larynx is to see the movement of bubbles as air passes in and out.

Bleeding, difficulty visualizing the airway, extrinsic and intrinsic pressure on the airway causing distortion and obstruction are concerns.

Airway concerns: Airway compromise can occur in an emergency situation due to infection and hemorrhage causing rapid increase in size of swelling. Large CHs may obstruct the airway and make identification of laryngeal inlet difficult. Principles of management of the difficult airway if upper airway obstruction is suspected. Involvement of base of tongue and oropharynx is common and may cause obstruction to breathing.

Prepare a selection of endotracheal tubes and laryngoscope blades. Intubation may be difficult because of distortion of the airway. Different options for intubation include direct laryngoscopy, blind nasal, fiberoptic, tracheostomy under LMA, tracheostomy under local anesthesia.

Fiberoptic intubation with sedation and topical anesthesia such as 2% to 4% lidocaine, which may be sprayed via the suction channel of the scope onto the vocal cords to minimize the incidence of laryngospasm before the FOB is inserted into the trachea. This can allow placement of Cook airway exchange catheter over guidewire. In the setting of difficult intubation, placement of laryngeal mask airway for urgent tracheostomy has been described.

Positive pressure ventilation with CPAP during expiration will prevent collapse of upper and lower airways.

c. Monitored anesthesia care

Benefits:A safe alternative method is awake fiberoptic intubation with light sedation and topicalization of airway. Useful when airway encroachment after induction or tracheostomy is considered difficult and allows airway to be secured prior to induction of general anesthesia.

Drawbacks: A child cannot fully cooperate to intubation under sedation.

Other issues: Sedation with atropine, midazolam, and ketamine and topicalization of 4% lidocaine to the vocal cords. Consider using dexmedetomidine.

6. What is the author's preferred method of anesthesia technique and why?

In children of more than 1 year of age, premedication with oral midazolam can be carefully titrated in patients with normal airway. Avoid premedication in setting of difficult airway.

If the lesion is small and the child has a normal airway, then inhalation or intravenous induction of anesthesia can be applied. If lesion is large, inhalation induction oxygen, nitrous oxide and sevoflurane maintaining spontaneous ventilation until larynx is visualized and trachea intubated. Coughing and breath-holding and/or laryngospasm during attempts at intubation may be minimized by administering propofol (1-2 mg/kg) and lidocaine 1.5 mg/kg IV. Intubate, preferably using an armored tube, and secure the tube firmly. If intraoral dissection is planned, a nasal tube may be preferable. In the case of a difficult intubation, insert an oral tube first then change to a nasal tube is this is possible without further airway compromise.

If the clinician is unable to visualize vocal cords, place LMA then fiberoptic bronchoscope for ETT placement. After the induction of anesthesia, large bore venous access is necessary. Maintain anesthesia with nitrous oxide, relaxant, fentanyl, and sevoflurane with controlled ventilation. For large tumors requiring extensive dissection, an arterial catheter should be inserted. Beware of vagal reflexes during dissection in the neck. Give atropine IV if these reflexes occur. Replace blood loss carefully with fluids guided by the blood pressure and measured losses.

What prophylactic antibiotics should be administered?

Prophylactic antibiotic received within one hour prior to surgical incision. First- or second-generation cephalosporins satisfy the criteria for most operations. If a patient is allergic to beta-lactams, fluoroquinolones and clindamycin in selected situations. Prophylactic antibiotics are discontinued within 24 hours after surgery end time. (Downloaded from SCIP (August 13, 2011), "CMS Core Measure SCIP Surgical Care Improvement Project," at http://www.sjhlex.org/documents/Physicians/SCIP_Poster_Full_Size.pdf.)

What do I need to know about the surgical technique to optimize my anesthetic care?

Need to know size and extent of CH. If the lesion is extensive, extubation should be delayed until the extent of postoperative swelling is determined. A few children may need tracheostomy. Children who present with small lesion may awakened and extubated in the OR.

What can I do intraoperatively to assist the surgeon and optimize patient care?

Maintain vigilance for potential airway complications of the patient. When intraoral extension of tumor is present, ask surgeon if nasal endotracheal tube desired. Communicate if any vagal reflexes occur intraoperatively. Extubate the patient smoothly and prevent excessive coughing or bucking, which might cause bleeding at the surgical site. Consider placement of arterial catheter.

a. Neurologic:

N/A

b. If the patient is intubated, are there any special criteria for extubation?

Resolve postoperative swelling in the case of extensive surgery adjacent to the airway.

c. Postoperative management

What analgesic modalities can I implement?

Titration of opioid analgesics, such as morphine 0.05 mg/kg (avoid large doses).

What level bed acuity is appropriate?

Close observation in the PICU or PACU overnight is necessary because of the danger of bleeding into the surgical site or compression of the airway. If intubated, administer chest X-ray to confirm tube position and humidified oxygen. Postoperative ventilation may be necessary if intubation difficulties were encountered or surgical excision rendered floor of mouth less firm.

What are common postoperative complications, and ways to prevent and treat them?

Postoperative complications occur in 30% or more cases, including fluid collection at the site of the lesion, hematoma, facial nerve palsy, laryngeal edema, airway obstruction, pneumonia, infection, Horner’s syndrome, recurrent laryngeal nerve palsy, and damage to the spinal accessory and marginal mandibular nerves and hypoglossal nerve.

Airway and swallowing problems may persist after surgery because of mucosal edema, loss of neural innervation to pharynx or tongue, and enlargement of internal lymphangiomas. Recurrence of CH following surgical excision may occur within 1 year.